I was just wondering if there is anyway to add a layer to Basecamp or Mapsourse.The problem I am having is I brought software for gps snowmobiling and when I bring in up on map sourse or base camp I can't tell where I am on the map because it only show the trails with no other info like town lines,roadsor even topo is the anyway to add a map layer under my software on Basecamp..

BaseCamp can only show one map product at a time, at least for now, maybe later versions will permit showing multiple map products. However, if you can find a transparent topo overlay map for your area of interest you should be able to view both the topo and the snowmobile product at the same time on a Garmin GPSr that supports maps.

Well that is not completely true. Basecamp can show a raster based map at the same time as a transparent overlay. So you could see if there are any Garmin Custom Maps (.kmz files) available for your area here. Go to http://www.gpsfiledepot.com/maps/ and click the box that says "Garmin Custom (Imagery)" in the lower left corner of the window, then click the Filter button.

Alternately, you could purchase Garmin Birdseye Topo if your GPS is compatible. This will give you scans of USGS 24k topo maps for the entire US for $30. These maps should be able to be displayed at the same time as a transparent overlay also. However, you must have a newer Garmin handheld device that is compatible or you will not be able to purchase these.